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Inactive ingredients play supporting role in dietary supplements

April 23, 2008

6 Min Read
Inactive ingredients play supporting role in dietary supplements

What's a good movie without extras? While not the stars of the film, extras support the leading characters, providing cohesion and flow for the movie. It turns out that extras, or excipients, in dietary tablets and capsules play a similar role—they're essential to high-quality supplement function, but they're not the reason consumers buy the product.

But sometimes a supplement uses too much filler, or even worse, a potentially toxic one. Consumers are becoming increasingly conscientious about reading labels, wondering exactly what that list of inactive ingredients is all about.

"We do have consumers that are very knowledgeable, and we get questioned all the time about the function and purpose of inactive ingredients," says Marci Clow, senior director of technical services at Rainbow Light Nutritional Systems, based in Santa Cruz, Calif. "It's a big concern for consumers."

Depending on the form of the supplement, excipients may be necessary to allow it to function as a whole and to ensure the consumer reaps all of its benefits.

Drying or anti-caking agents
These ingredients help ensure the tablets and capsules are created with uni?form weight and shape, according to Massood Moshrefi, vice president of operations and technical services for InterHealth Nutraceuticals, based in Benicia, Calif. "Furthermore, in cases where you have to minimize adhesion between particles, you might use anti-caking agents," he says.

An example of an anti-caking compound is silicon dioxide, which occurs naturally in the form of flint, quartz and opal. It's harmless when consumed in small amounts because it is indigestible and passes through the gastrointestinal tract without leaving a trace. New Chapter Organics uses silica, a form of silicon dioxide, as a drying agent that makes the powder flow consistently in the powder press, according to Paul Schulick, founder and co-chief executive officer of the Brattleboro, Vt.-based company.

Some anti-caking agents aren't so innocuous, however. Calcium silicate and calcium phosphate are "undesirable because they may cause irritation upon contact, and may bind up minerals, decreasing their bioavailability," Clow says.

Binders help hold the particles in a tablet together. Several natural, harmless binders are available for supplement manufacturing. Rainbow Light uses cellulose or microcrystalline cellulose, a plant fiber from trees; gum acacia or gum arabic, a vegetable gum; stearic acid, which is derived from palm and coconut oils; and magnesium stearate.

The source of magnesium stearate is typically beef, but more manufacturers are opting for nonmeat sources such as vegetable oil. "If it's coming from a beef source, it's less preferred because processing would require animal fats that often contain fat-soluble toxins like PCBs and dioxins," says Jason Dewberry, vice president of marketing for West Palm Beach, Fla.-based Garden of Life.

Moisture protectors
Some tablet ingredients need to be shielded from moisture in the air; a natural vegetable cellulose coating will usually do the trick. "The advantage of this ingred?ient is that it is free from sugar and allergens. Some manufacturers might use shellac, zein [a plant protein] or polysaccharides instead," Moshrefi says.

Retailers and consumers should be especially wary of ingredients like shellac and talc, which are used in building materials and should not be ingested. "We try to use only food-based excipients; shellac is an industrial painting material, not a food, and talc is a potential carcinogen upon ingestion; inhalation can cause lung problems similar to those from asbestos," Clow says. Also, to prevent allergic reactions, coatings containing lactose or soy should be avoided.

Disintegrants are a necessary component of most tablets because they allow the tablet to expand and break down in the diges?tive tract. Examples are starches, cellulose, sodium carboxymethyl cellulose or polyvinyl pyrrolidone. While many ingredients in this category are named for their chemical compounds, none is toxic. Rainbow Light uses a modified version of cellulose, for instance, called croscarmellose sodium, which is derived from the bark of birch, fir or walnut trees.

While many tablets don't require preservatives because of their low moisture content, some might contain trace amounts, as will gel-tabs or liquid vitamins. "Ascorbic acid can be added to a product to protect against oxidation of the product, or to add nonnatural vitamin C," Dewberry says.

Many questionable preservatives are on the market, however. One to watch out for is BHA (butylated hydoxyanisole), which is only allowed at .02 percent, and may affect liver and kidney function, according to Clow. Another harmful preservative is BHT (butylated hydroxytoluene). "Studies of BHT show it causes chemical brain changes and abnormal behavior patterns in offspring of mice that had it added to their food, and use of it is prohibited in England," Clow says. And be especially careful of liquid supplements that contain ascorbic acid and either potassium benzoate or sodium benzoate, because the combination can form benzene, a chemical linked to cancers, according to a study published by the U.S. Food and Drug Administration in March 2006.

To fill out the size of a tablet or capsule so that it's consumable, manufacturers can use ingredients such as plant cellulose, lactose, glucose, sucrose, mannitol, sorbitol and dibasic calcium phosphate, Moshrefi says.

The safest fillers are always food-based, but even some of those are questionable. Sorbitol, for instance, is a sugar alcohol, but can cause diarrhea if ingested in large doses, and it may also alter the effectiveness of some drugs, Clow says.

Because New Chapter Organics is an organic supplements line, it cannot rely on any chemicals for its fillers. "We use organic pre-gelatinized maize starch, organic gum acacia and silica. We are experimenting with an organic barley grass, silica and organic gum acacia system," Schulick says.

As a general rule, it's best to look for products that contain the least amount of fillers and the highest percentage of active ingredients.

"We believe that it's critical to get as many active ingredients in the product as possible, that the delivery dosage is as densely packed with nutrients as it can be," Dewberry says. "While fillers are necessary, we try to avoid them as much as we can."

Filling in the rest
The most effective supplements are usually priced higher precisely because they contain fewer excipients. "If you're using close to 100 percent active ingredients, the product is inevitably going to cost more, but you're also going to get more out of it. And this, in turn, will lead to customer loyalty because they're going to feel a difference that they wouldn't from using a supplement full of additives and fillers with no nutritional value," Dewberry says.

And while it's important to have some variety on your shelves, it might be helpful to pare down your selection of supplements to help consumers feel less inundated with choices, Dewberry says.

"The challenge to the retailer is to provide a more palatable offering to consumers—with so many choices, there can't be any depth of understanding for each product. If you [reduce] the number of SKUs you carry, you'll make the supplements aisle more translatable to the consumer," he says.

While many retailers might balk at cutting back on options, Dewberry believes that doing so will not only increase customer loyalty and protect private stores from competition from the Internet and large chain stores, but also increase sales. "There's a difference between profit margin and percent margin. If you're carrying only a couple premium products, sure they're priced higher and the percent margin isn't the same, but the profit margin will be a lot higher," he says.

Christine Spehar is a Boulder, Colo.-based freelance writer.

Natural Foods Merchandiser volume XXVIII/number 9/p. 98, 100

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